# Better than Runge-Kutta-Fehlberg 4(5) at high order?

I wonder what are currently the best numerical solvers of ODE for high-accuracy computations. I need an efficient and accurate method to solve ODE that are not pathological (all is smooth) using 128-bit floating-point number (quad arithmetics).

So, what would be good choices (some references comparing different algorithms would be appreciated) ?